The coping is the capstone for the beam, and is used to finish the pools edge and bring it up flush with the pool deck. Pre-cast concrete coping with a bull-nose front edge has been the standard for many years. Modern designs are making use of bull-nose brick coping in many colors and textures. Flagstone is also a popular choice. The pool without coping has been accomplished with the cantilever deck. Inspired by Frank Lloyd Wright’s designs, the cantilever deck extends over the edge of the pool, and is free-floating. [No coping] Vinyl liner pools have their coping attached to the wall, and is usually C – shaped, such that the pool deck is poured into the coping. A typical vinyl liner pool, or a pool with a cantilever deck do not require caulking of an expansion joint, because, there is none.
First question to be asked is “have you caulked your expansion joint?” Freezing water in the joint will put pressure on the coping, breaking the mortar that attaches it to the beam. Second question will be “Is the expansion joint true, or does the pool deck touch the coping?” This pushes on the coping (and the beam) every time the deck or the pool expands.
Crumbling mortar joints between coping stones?
If there is only a small check crack, it’s probably not a problem. Cracking large enough to allow water to seep in will create havoc. We also want to note the possible reasons for this mortar joint to be crumbling. It could be just chemical breakdown or a bad mix, or there could be a directional force applying pressure to the area.
Typical costs for removal and replacement of pre-cast coping average $25 per linear foot. Add a few more $ for bull-nose brick, and a few more than that for custom cut flagstone coping. To repair yourself, use a chisel and hammer and perhaps a cut saw to carefully pull up the loose stone. Carefully chip old mud off of it, and off of the beam, and reset it in a new bed of mud or thinset mortar. Once set, fill in the mortar joints between the stones.
Localized coping repair is billed hourly. When replacing or resetting a few coping stones, bear in mind that the new will be much brighter than the old. It is also difficult to pull up and reset coping stones because many break when coming up or when cleaning up the undersides. For this reason, many people with several, but not all bad stones, will replace all anyway. Especially if they’re changing styles or colors.